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Add Noise Module

Once a set of interferograms Ig 8, b) has been computed as the power incident on the detectors, the Add Noise Module determines the acmal signal measured by the system, by integrating the detector response and noise to the simulated interferograms. [Pg.95]

To add the photon noise contribution to the interferograms generated by the simulator, Igraw, the dominant term of the NEP considered is the shot noise. In this situation, photon noise follows Poisson statistics and it can be approximated by a Gaussian probability distribution. The generation-recombination contribution to the NEP is assumed to follow also Poisson statistics. The total NEP is calculated as [Pg.95]

In this situation, the standard deviation of the noise is on = NEP totalwhere At is the time interval or the inverse of the acquisition frequency facq- The acquisition frequency is defined as facq = 1/( tt) where r is the user defined number of time constants per acquisition. This aiv value is then multiplied by a random number generated vector, rand(S) and added to the raw interferograms as [Pg.95]

If the spectrometer is set to perform multiple scans (Ns, user defined parameter) for the same measurement, this process is performed Ns times. [Pg.95]

If the Instrument Simulator is set to include 1/f noise, it is added to the simulated interferograms along with the calculated NEP, as the white noise level e is effectively [Pg.95]


Once all the simulated noises are computed, they are added to the interferograms at the Add Noise Module to simulate more realistic measurements. The simulated interferograms are then sent to the Detector Module, where the interferograms are distorted according to the detector effects such as the time response. This interferograms are then sampled and readout at the Sampling and Readout Module, which also stores the data for the data reduction and processing. [Pg.75]

The Sky Simulator consists of two modules the Sky Generator Module and the Sky Photon Noise Module. The Sky Generator Module creates the input data cube to which a Double Fourier Modulation will be applied. Once the data cube is created, the Sky Photon Noise Module calculates the corresponding photon noise, that will be added to the interferograms at the Add Noise Module. [Pg.77]

Although the 1/f noise is computed within the Detector Module, it is included in the simulated interferograms at the Add Noise Module along with the other sources of noise. [Pg.94]

In an analysis/synthesis filter bank, all quantization errors on the spectral components show up on the time domain output signal as the modulated signal multiplied by the synthesis window. Consequently, the error is smeared in time over the length of the synthesis window / prototype filter. As described above, this may lead to audible errors if premasking is not ensured. This pre-echo effect (a somewhat misleading name, a better word would be pre-noise) can be avoided if the filter bank is not static, but switched between different frequency/time resolutions for different blocks of the overlap/add. An example of this technique called adaptive window switching is described below. [Pg.42]

The maximum entropy method was one of several techniques that were used to restore the Hubble images. However, all techniques were hampered by lack of complete knowledge of the point-spread function. Using a point-spread function that included errors (either because of noise in a measured point-spread function, or modeling imperfections in predicted point-spread function) further adds to the ill-posed nature of the restoration problem. Although the modulation transfer function tended not to be zero-valued (at least not as severely as in the radio interferometry case described below), this was of only small comfort when imaging weak objects, as the... [Pg.137]


See other pages where Add Noise Module is mentioned: [Pg.128]    [Pg.95]    [Pg.128]    [Pg.95]    [Pg.31]    [Pg.33]    [Pg.67]    [Pg.73]    [Pg.40]    [Pg.24]    [Pg.6524]    [Pg.150]    [Pg.24]    [Pg.6523]    [Pg.131]    [Pg.440]    [Pg.220]    [Pg.959]    [Pg.27]    [Pg.164]    [Pg.262]    [Pg.7]   


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Noise modulation

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